COEXISTING WITH BEAVERS...WILDLIFE SMART A beaver cuts an average of 216 trees per year. COEXISTING...
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WILDLIFE SMART A beaver cuts an average of 216 trees per year. COEXISTING WITH BEAVERS Beavers have many important ecological, economic, aesthetic, and intrinsic values. However, conficts with beavers can happen when they construct dams that cause fooding to people’s property and infrastructure, harvest valued trees and plants for food or dam construction, or when they transmit disease to people. There are things you can do to reduce the risk of conficts with beavers. This fact sheet offers some helpful advice to protect yourself, your family, your property, and beavers. THINGS YOU NEED TO KNOW ABOUT BEAVERS • A beaver cuts an average of 216 trees per year and prefers aspen, poplar, willow and birch. Harvested trees are used as a food source as well as in the construction of dams and lodges. • The inner tree bark is a beaver’s primary food for the winter; in the summer beavers mostly eat herbaceous plant materials such as grasses, leaves, fruits and aquatic plants. • Trees and plants most vulnerable to beaver damage are usually within 50 metres of a waterway used by beavers. Trees and plants are most at risk when food is plentiful and predators are more scarce. • Beavers construct dams to create ponds of water deep enough that they won’t freeze to the bottom in winter. A depth of about 0.6 to 0.9 metres of unfrozen water is required for beavers to access their lodge and stored food year-round, underwater, where they are safer from predators. • Beavers are stimulated to construct dams by the sound of running water. • Road culverts are frequently targeted for beaver dam construction, particularly when they are located on gently sloping (1 to 10 per cent) relatively wet land close to hardwood or mixedwood forest. The construction of a beaver dam in a culvert or adjacent to a road can result in back-fooding and a road washout. • Beavers can construct their den by building a lodge of branches and mud, or by digging holes in the bank of a lake, pond, river, creek or even a ditch. Dens in a ditch may extend under the road, and cause the road to cave in. • Beavers may carry diseases and parasites such as tularemia and giardia (commonly known as beaver fever) that can be transmitted to people. • Beavers tend to be most active at night, and will try to avoid interacting with people. However, like any wild animal, if a beaver encounters a person and feels cornered or threatened it may choose to attack.
Transcript of COEXISTING WITH BEAVERS...WILDLIFE SMART A beaver cuts an average of 216 trees per year. COEXISTING...
WILDLIFE SMART
A beaver cuts an average of 216 trees per year.
COEXISTING WITH BEAVERS Beavers have many important ecological, economic, aesthetic, and intrinsic values. However, conflicts with beavers can happen when they construct dams that cause flooding to people’s property and infrastructure, harvest valued trees and plants for food or dam construction, or when they transmit disease to people.
There are things you can do to reduce the risk of conflicts with beavers. This fact sheet offers some helpful advice to protect yourself, your family, your property, and beavers.
THINGS YOU NEED TO KNOW ABOUT BEAVERS
• Abeavercutsanaverageof216treesperyearand prefersaspen,poplar,willowandbirch.Harvested treesareusedasafoodsourceaswellasinthe constructionofdamsandlodges.
• Theinnertreebarkisabeaver’sprimaryfoodforthe winter;inthesummerbeaversmostlyeatherbaceous plantmaterialssuchasgrasses,leaves,fruitsand aquaticplants.
• Treesandplantsmostvulnerabletobeaverdamage areusuallywithin50metresofawaterwayused bybeavers.Treesandplantsaremostatriskwhen foodisplentifulandpredatorsaremorescarce.
• Beaversconstructdamstocreatepondsofwater deepenoughthattheywon’tfreezetothebottomin winter.Adepthofabout0.6to0.9metresofunfrozen waterisrequiredforbeaverstoaccesstheirlodgeand storedfoodyear-round,underwater,wheretheyare saferfrompredators.
• Beaversarestimulatedtoconstructdamsbythesound ofrunningwater.
• Roadculvertsarefrequentlytargetedforbeaverdam construction,particularlywhentheyarelocatedon gentlysloping(1to10percent)relativelywetlandclose tohardwoodormixedwoodforest.Theconstruction ofabeaverdaminaculvertoradjacenttoaroad canresultinback-floodingandaroadwashout.
• Beaverscanconstructtheirdenbybuildingalodge ofbranchesandmud,orbydiggingholesinthebank ofalake,pond,river,creekorevenaditch.Densina ditchmayextendundertheroad,andcausetheroad tocavein.
• Beaversmaycarrydiseasesandparasitessuchas tularemiaandgiardia(commonlyknownasbeaver fever)thatcanbetransmittedtopeople.
• Beaverstendtobemostactiveatnight,andwilltry toavoidinteractingwithpeople.However,likeany wildanimal,ifabeaverencountersapersonandfeels corneredorthreateneditmaychoosetoattack.
THINGS YOU CAN DO TO REDUCE THE RISK OF CONFLICT
Reduce risks to people
• Donotapproachabeaveroritslodge/den. Avoidphysicalcontactwithbeaversandtheirfeces.
• Ifyouencounterabeaverthatappearssickor injured,makenoteofitslocationandreportitto aconservationofficer.
• Priortodrinkinganywaterinwhichbeaversmaybe found,boilitforaminimumofoneminuteorensure ithasbeenadequatelyfilteredorchemicallytreated.
• Whenhandlingharvestedbeavers,usegoodquality rubberglovesandthoroughlywashyourhandswith soapandwaterafterhandlingbeaversorcominginto contactwithwaterwheretheymaybepresent.
Reduce risks to valued trees and plants
• Wiremeshfencingcanbeinstalledaroundthebase ofanindividualtree,oragroupoftreesorplantsfor protectionfrombeaverdamage.Meshisrecommended tobefour,six,oreightgauge,withopeningsnot largerthan10centimetresby10centimetres,and aminimumheightof1.5metres.Fencingshouldbe installedincontactwiththegroundandsecuredwith landscapingstaples.Whenfencingindividualtrees, besuretoallowspacebetweenthetrunkandthe fencingforthetree’sgrowth.
• Electricfencingcanbeinstalledataheightof 10centimetresabovethegroundtoprotectagroup oftreesorplants.
Reduce the risk of beaver dams causing flood damage to adjacent land and infrastructure Install pond levelers
• Apondlevelerreducesandmaintainspondwaterto adesiredlevel.Thepondlevelershouldbeinstalled atalevelthat(1)allowstheresidentbeaverstothrive (typicallyaminimumdepthofaboutonemetreatthe beaverlodgeentrance),and(2)preventsthepond watersfromnegativelyimpactingadjacentlandor infrastructure.
• Writtenauthorizationfortheuseofapondleveler isrequiredbeforeinstallation.Contactaconservation officertorequestauthorization.Youwillneedto providealegallanddescriptionofthedesiredlocation.
• Apondlevelercanbeinstalledthroughabeaverdam orintoaculvert.
• Themultipleholesonthepondlevelerintakeend allowfortheslow,quietmovementofwater,and discouragedammingbehaviourbyabeaver.Studies haveshownthatbeaverdammingbehaviouris stimulatedbythesoundofrunningwater,andwhen thatsoundisremoved,abeaverisnotmotivatedto buildorrepairadam.
• Thescreenedintakeareaofthelevelerkeepsdebris outanddiscouragesplugging.Pondlevelerstypically needsomemaintenancetoensurethescreenedintake areastayssufficientlyclearofdebristoallowadequate water-flow.Pondlevelersareconsideredtobea longer-termsolutionfordammanagement,andwith maintenance,canbeeffectiveforseveralyears.
• Instructionsfortheconstructionandinstallationofpond levelersareavailablefromWildlifeandFisheriesBranch ([email protected]).
PONd LEVELER
Pond levelers can be used to reduce and maintain a beaver pond’s water level at a desired depth.
Install beaver deceivers
• Beaverdeceiversarerecommendedforinstallationon culvertsthatareatgreaterriskforbeaverblockage.
• Wheresiteconditionsallow,themosteffectivebeaver deceiveristhetrapezoidal(four-sided)fencingsystem, withaminimumtotallengthof14metres,plusatop andbottomside.Whenbuilttothesespecifications, abeaverdeceivertypicallyrequireslittlemaintenance andcanbeeffectiveformanyyears.
• Beaverdeceiversareusuallybuilton-siteandadjusted asneededtomeetthesite’srequirements.Ifthe groundisunevenwhereinstallationisrequired, levelingthegroundwillallowforeasierinstallation.
• Instructionsfortheconstructionandinstallationof beaverdeceiversareavailablefromWildlifeand FisheriesBranch([email protected]).
BEAVER dECEIVER
Beaver deceiver fencing can be used to lower the risk of culvert blockage by beavers.
Remove beaver dams
• Removingabeaverdamisgenerallyatemporary solutionandshouldonlybeconsideredafterother techniqueshavebeentriedoriftheyareunsuitable forthearea.Althoughthelethalremovalofthe beaversassociatedwiththedamwilltypicallybe requiredpriortothecommencementofbeaverdam removalactivities,ifthehabitatremainssuitable, morebeaversarelikelytomoveintotheareaand willconstructnewdams.
• Writtenauthorizationforbeaverdamremovalis requiredbeforeanydamremovalactivitiesare undertaken.Contactaconservationofficertorequest authorization.Youwillneedtoprovidealegalland descriptionofthedamlocation.
• Clearingbeaverdebrisfromaculvertdoesnotrequire priorauthorization.
• FollowManitoba’sBeneficialManagementPractices forBeaverDamRemoval.
LETHAL BEAVER REMOVAL • Beaverscanbeharvestedbyalicensedtrapper duringtheregulatedseason,whereitislawfultodo so.Alltrappingregulationsapply.Itisrecommended thatlandownersinareaspronetoconflictswith beaversworkproactivelywithlocaltrappersfor beaverpopulationmanagement.Beaverharvestis bestconductedwhentheirpeltisprime(Januaryto March)toensurethepeltisnotwastedanditsvalue ismaximized.Makearrangementswithalocaltrapper wellinadvanceoftheprimetrappingseasonsothat theycanbepreparedtoharvestbeaversonyourland atthattime.
• Inexceptionalcircumstances,underTheWildlifeAct, alandownermaykillabeaverindefenceoftheir propertyandtheymustreportthekillingofthebeaver toaconservationofficerwithin10days.
• Aspecialpermitmustbeobtainedfromaconservation officerifalandownerwantsadesignatetoremove abeaverontheirbehalfonlandtheyown.Aspecial permitwouldalsoberequiredbeforethelethal removalofabeaveronleasedland.Contacta conservationofficerinthelocaldistrictofficeto requestapermit.
• Somepestcontrolcompaniesareauthorizedto removebeaverforpestmanagementpurposes.
Beaver dams help to increase biodiversity, improve water quality, and recharge ground water supplies in a watershed.
WHY NOT JUST RELOCATE BEAVERS?
Relocating beavers can create a new set of problems for the beavers, other wildlife, and people:
• Therelocatedbeavermaybeattackedandseriously injuredbytheresidentbeavers.
• Relocatedwildlifemaycarrydiseasestowildlifeinthe releasearea.
• Relocatingbeaverslateintheseasonmaynotleave themenoughtimetobuildtheirlodgesandstore enoughfoodtosurvivethewinter,leavingthem vulnerabletodeathbystarvationorexposure.
• Therelocatedbeaversmaycauseconflictswithnew, surroundinglandowners.
Road culverts are frequently targeted by beavers for dam construction.
BENEFITS OF BEAVER DAMS
Beavers provide many ecological, economic and aesthetic benefits. A few of these benefits include:
• Beaverpondssignificantlyincreaselocalbiodiversity bycreatingriparianandwetlandhabitatsthatcan supportavarietyofwildlifeincludinginvertebrates, fish,amphibians,waterfowl,andsmallmammals.
• Standingdeadtrees(snags)thatremaininbeaver floodedareasprovidefood(insects),restingplaces, andnestingcavitiesformanybirdspecies.
• Theincreasedpresenceoffishandwildlifeinlarger beaverpondareasresultsinincreasedhunting,fishing, andwildlifeviewingopportunitiesforpeople.
• Beaverdamsimprovedownstreamwaterqualityby trappingandstoringsediment,andreducetheloss ofsedimentfromtheforestecosystem.
• Thesedimentleftbehindwhenthebeaversabandon anareacanresultinafertilemoistmeadow.
• Beaverpondsincreasethesurfaceareaandvolume ofwaterinawatershedandassistwiththerechargeof groundwatersupplies.Increasedsurfaceandground watersuppliesimprovesaccesstowaterforlivestock andhelpswithdroughtresilienceforfarmproduction.
• Well-maintainedbeaverdamscanhelpreducewater lossthroughrunoff,andcanmoderatepeakflowsof floodingevents.
For more information on reducing the risk of conflicts with beaver and other wildlife, visit www.manitoba.ca/human-wildlife.
To report wildlife showing aggressive behaviour, or that appears sick, injured, or orphaned, contact a conservation officer at the local district office
or call the TIP line at 1-800-782-0076.
